diff --git a/src/main/java/org/redkale/convert/json/JsonBytesWriter.java b/src/main/java/org/redkale/convert/json/JsonBytesWriter.java
index 77ecdf95e..f47440845 100644
--- a/src/main/java/org/redkale/convert/json/JsonBytesWriter.java
+++ b/src/main/java/org/redkale/convert/json/JsonBytesWriter.java
@@ -519,7 +519,7 @@ public class JsonBytesWriter extends JsonWriter implements ByteTuple {
             byte b2 = src[i + 1];
             i += 2;
             if (b2 == 0 && b >= 0) {
-                if (b == '"') {
+                if (b == BYTE_DQUOTE) {
                     bytes[curr++] = '\\';
                     bytes[curr++] = '"';
                 } else if (b == '\\') {
@@ -552,12 +552,12 @@ public class JsonBytesWriter extends JsonWriter implements ByteTuple {
                 if (c < 0x800) {
                     bytes[curr++] = (byte) (0xc0 | (c >> 6));
                     bytes[curr++] = (byte) (0x80 | (c & 0x3f));
-                } else if (Character.isSurrogate(c)) {
+                } else if (c >= MIN_HIGH_SURROGATE && c < MAX_LOW_SURROGATE_MORE) { // Character.isSurrogate(c)
                     int uc = -1;
-                    if (Character.isHighSurrogate(c) && i < len) {
+                    if (c < MAX_HIGH_SURROGATE_MORE && i < len) { // Character.isHighSurrogate(c)
                         char c2 = (char) ((src[i] & 0xff) | ((src[i + 1] & 0xff) << 8));
-                        if (Character.isLowSurrogate(c2)) {
-                            uc = Character.toCodePoint(c, c2);
+                        if (c2 >= MIN_LOW_SURROGATE && c2 < MAX_LOW_SURROGATE_MORE) { // Character.isLowSurrogate(c2)
+                            uc = (c << 10) + c2 + MIN_SUPPLEMENTARY_CODE_POINT_MORE;
                         }
                     }
                     if (uc < 0) {
@@ -583,6 +583,16 @@ public class JsonBytesWriter extends JsonWriter implements ByteTuple {
         count = curr;
     }
 
+    private static final char MIN_LOW_SURROGATE = '\uDC00';
+    private static final char MAX_LOW_SURROGATE = '\uDFFF';
+    private static final char MIN_HIGH_SURROGATE = '\uD800';
+    private static final char MAX_HIGH_SURROGATE = '\uDBFF';
+    private static final int MIN_SUPPLEMENTARY_CODE_POINT = 0x010000;
+    private static final char MAX_LOW_SURROGATE_MORE = MAX_LOW_SURROGATE + 1;
+    private static final char MAX_HIGH_SURROGATE_MORE = MAX_HIGH_SURROGATE + 1;
+    private static final int MIN_SUPPLEMENTARY_CODE_POINT_MORE =
+            (MIN_SUPPLEMENTARY_CODE_POINT - (MIN_HIGH_SURROGATE << 10) - MIN_LOW_SURROGATE);
+
     private void writeEscapeLatinString(final boolean quote, byte[] value) {
         byte[] bytes = expand(value.length * 2 + 2);
         int curr = count;
@@ -590,7 +600,7 @@ public class JsonBytesWriter extends JsonWriter implements ByteTuple {
             bytes[curr++] = BYTE_DQUOTE;
         }
         for (byte b : value) {
-            if (b == '"') {
+            if (b == BYTE_DQUOTE) {
                 bytes[curr++] = '\\';
                 bytes[curr++] = '"';
             } else if (b == '\\') {
@@ -667,7 +677,7 @@ public class JsonBytesWriter extends JsonWriter implements ByteTuple {
     }
 
     @Override
-    public String toString() {
+    public final String toString() {
         return new String(content, 0, count, StandardCharsets.UTF_8);
     }
 
diff --git a/src/main/java/org/redkale/convert/json/JsonStreamWriter.java b/src/main/java/org/redkale/convert/json/JsonStreamWriter.java
index def9f8dfb..f0b490327 100644
--- a/src/main/java/org/redkale/convert/json/JsonStreamWriter.java
+++ b/src/main/java/org/redkale/convert/json/JsonStreamWriter.java
@@ -57,6 +57,15 @@ class JsonStreamWriter extends JsonByteBufferWriter {
         }
     }
 
+    @Override
+    public void writeTo(final byte[] bs, final int start, final int len) { // 只能是 0 - 127 的字符
+        try {
+            out.write(bs, start, len);
+        } catch (IOException e) {
+            throw new ConvertException(e);
+        }
+    }
+
     @Override
     public void writeTo(final char[] chs, final int start, final int len) {
         writeTo(false, chs, start, len);
diff --git a/src/main/java/org/redkale/util/Utility.java b/src/main/java/org/redkale/util/Utility.java
index d0ef93081..903178b16 100644
--- a/src/main/java/org/redkale/util/Utility.java
+++ b/src/main/java/org/redkale/util/Utility.java
@@ -314,10 +314,11 @@ public final class Utility {
                             StringBuilder.class.getSuperclass().getDeclaredField("value"));
                     final long fd3 = unsafe0.objectFieldOffset(String.class.getDeclaredField("coder"));
                     final long fd4 = unsafe0.objectFieldOffset(Buffer.class.getDeclaredField("address"));
-
+                    Field cf = String.class.getDeclaredField("COMPACT_STRINGS");
+                    final boolean compact = unsafe.getBoolean(String.class, unsafe0.staticFieldOffset(cf));
                     strByteFunction0 = (Object t) -> unsafe.getObject(t, fd1);
                     sbByteFunction0 = (Object t) -> unsafe.getObject(t, fd2);
-                    strLatin1Function0 = (Object t) -> unsafe.getByte(t, fd3) == 0; // LATIN1:0  UTF16:1
+                    strLatin1Function0 = (Object t) -> compact && unsafe.getByte(t, fd3) == 0; // LATIN1:0  UTF16:1
                     bufferAddrFunction0 = (Object t) -> unsafe.getLong(t, fd4);
                 }
                 { // signalShutdown